Apple Desktop Computer manual USB Ports, USB Connectors

C H A P T E R 3

Devices and Ports

This chapter describes both the built-in I/O devices and the ports for connecting external I/O devices. Each of the following sections describes an I/O port or device:

■“USB Ports”

■“Keyboard”

■“Mouse”

■“Hard Disk Drive”

■“Video Display”

■“Infrared Communication Link”

■“Sound System”

■“Ethernet Port”

■“Internal Modem”

USB Ports

The iMac computer has two Universal Serial Bus (USB) ports that are used to connect the keyboard and mouse as well as additional I/O devices such as printers, scanners, and low-speed storage devices.

For more information about USB on the Macintosh computer, refer to Apple Computer’s Mac OS USB DDK ATI Reference. Information is also available on the World Wide Web, at:

http://developer.apple.com/dev/usb/

For full specifications of the Universal Serial Bus, refer to the USB

Implementation Forum on the World Wide Web, at:

http://www.usb.org/developers/index.html

USB Connectors

The USB ports use USB Type A connectors, which have four pins each. Two of the pins are used for power and two for data. Figure 3-1 is an illustration of a Type A port and matching connector. Table 3-1 shows the pin assignments.

28USB Ports